James a



(No Model.)

J. A. MALONEY.

PNEUMATIC ACOUSTIC TELEPHONE.

No. 338,995. Patented Mar. 30, 1886.

INVENTOR- WITNESSES:

PETERS, mmmm w, w-anw n. c.

' UNITED STATES PATENT OFFICE.

JAMES A. MALONEY, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OF ONE-HALF TO HENRY D. OOOKE, OF SAME PLACE.

PNEUMATIC ACOUSTIC TELEPHONE.

SPECIFICATION forming part Of Letters Patent NO. 338,995, dated March 30, 1886.

Application filed July 2, 1885. Serial No. 170,506. (No model.)

To all whom it may concern Be it known that I, JAMES A. MALONEY, a citizen of the United States, residing at Washington, in the District of Columbia, have i11- vented certain new and useful Improvements in Pneumatic Acoustic Telephones; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to pneumatic acoustic telephones; and it has for its object the construction of a transmitter through which ar ticulate or other sounds may be conducted to a tube containing air under atmospheric pressure, by which said-sounds are conveyed to any desired distance and rendered audible through the medium of a proper receiver.

It has heretofore been proposed to convey sounds through tubes containing a body of confined airor fluids under pressure, the tube being provided at each end with a fixed diaphragm contained in a suitable chamber. The confined fluid in each case has been made the medium of transmitting the sound-waves produced by the human voice being directed against the diaphragm. None of these devices have given satisfaction, nor have they come into public use, for the reason that, owing to the rigidity of the diaphragm and its limited amount of vibration, and the pressure of the fluid upon the inner side of the diaphragm, the person using the instrument is required to expend considerable force upon the dia phragm to cause it to vibrate, and in consequence thereof only loud sounds produced at one end of the line are rendered audible at the other, and precludes the possibility of delivering a message without having it heard by other persons in the room with the speaker.

By my invention the tube or sound-conveyer is filled with air under atmospheric pressure, and is open at each end through the mouthpiece of the transmitter. The transmitter is so constructed that the sounds entering it through the mouth-piece are reflected and concentrated by a curved wall, and directed upon the column of free air contained in the tube, without the intervention of a diaphragm.

Reference being had to the accompanying drawings, which form part of this specification, Figure 1 represents a top view showing the transmitter in horizontal cross-section. Fig. 2 is a vertical section of the receiver used in connection with the transmitter.

A A designate the transmitters, attached to each end of a tube or sound-conveyer, B, which may be made of metal, paper, rubber, or any suitable material, and of any desired length.

The transmitter is represented as a rectangular frame or box, in which is formed a chamber having a curved wall, 0, made of paper or other thin material, and provided with an aperture, D. The frame or body of the transmitter may, however, be formed in the shape of the partition 0, and thus dispense with the latter.

E designates a partition or deflector, arranged between the inlet from the mouthpiece G and the outlet to the receiver H, the function of which is to direct the sound-waves from the mouth-piece against the curved wall 0, and like waves being transmitted from the tube B into thereceiver H.

A flaring mouth to the tube B is formed at I in the body of each transmitter, to concentrate the sound-waves received upon the wall 0, and direct them with the least amount of obstruction into the said tube.

The wall of the partition E is curved on the side next to the mouth-piece and straight on the opposite side, the curved wall serving to deflect the sound-waves against the curved wall 0, thus avoiding any angular projections 8 5 against which the waves can strike. The receiver H is attached to the metallic elbow a by means of a flexible connection, I), which is surrounded by a metallic tube, 0, forming a part of the receiver. The flexible connection 0 enables the person using the instrument to place the receiver to the car while using the transmitter.

Sounds coming through the chamber from any portion of the line are directed by the partition E into the receiver H, and as all confined fluids seek the easiest and most ready path of escape, the air put in motion by the vibrations produced by the sound-waves will naturally pass toward the receiver.

The receiver H is made in two sections, K L, suitably secured together, and is provided with a resonating-chamber, M M, in each section. Between said chambers is secured a fixed perforated diaphragm, N, and upon the outside of said diaphragm N is placed a mov'- able diaphragm, O, which is secured at one point only, and vibrates freely between the 'fixed diaphragm and anannular shoulder, d,

formed on the section K of the receiver.

In another application of even date of filing, No. 170,505, the receiver forms subject-matter of claims, and need not, therefore, be herein more fully described.

Having thus fully described my invention, what I claim is- 1. A sound-transmitter having a chamber formed between its walls and provided with a partition dividing the chamber throughout a'portion of its length into two channels, one of which transmits and the other conducts articulate or other sounds to a receiver, substantially as described.

2. Asound-transmitter provided with a partition attached to one side of the case, projecting part way across the chamber and forming separate channels leading to a mouth-piece 25 and a receiver, substantially as described.

3. A sound-transmitter provided with a partition having a curved deflecting-surface formed on one side and a plain surface on the opposite side, substantially as described.

4. A sound-transmitter having a chamber provided with curved walls and a deflectingpartition, substantially as described.

5. A sound-transmitter provided with a partition projecting into the chamber and 35 forming separate channels communicating with a sound-conveying tube, in combination with a mouth-piece and a receiver attached to the transmitter, substantially as described.

In testimony whereof I aflix my signature in 0 presence of two witnesses.

JAMES A. MALONEY.

\Vitnesses:

C. A. NEALE, WM. E. DYRE. 

